The invention relates to a capsule for containing beverage ingredients, the capsule being designed for insertion in a beverage production device in which a liquid under pressure enters the capsule to drain a beverage from the capsule, wherein the capsule comprises a circumferential first wall, a second wall closing the circumferential first wall at a first end, and a third wall closing the circumferential first wall at a second, open, end opposite the second wall, the first, second and third wall enclosing an inner space comprising the beverage ingredients, wherein the capsule comprises a sealing member for achieving a sealing effect between the capsule and the beverage production device.
EP 1700548 (EP'548) discloses a capsule comprising a cup-like base body and a closing foil member. The known capsule is designed for insertion in a beverage production device in which a liquid under pressure enters the capsule in order to interact with ingredients in the capsule and to drain a beverage from the capsule.
According to EP'548, it has to be assured that during operation, the only water flow is actually taking place through the interior of the capsule and that no water can flow from the water injector into the interstice between an annular enclosing member and the exterior of the capsule and then to the draining bore of the device. According to EP'548, in a known system, any water flow exterior to the capsule is stopped by a sealing engagement, that is achieved by a pinching engagement between the annular member, the flange-like rim of the side wall of the capsule and a capsule holder.
Also according to EP'548, an improvement could be thought of according to which the sealing engagement is further improved by lining the inner wall of the annular member with a rubber-elastic material. With other words, according to said approach the sealing engagement is assured by structures fixed to or attached with the beverage-producing device.
EP'548 aims at an improvement of the sealing engagement positioned between the liquid inlet and the beverage draining side of such a beverage production system. To that aim, EP1700548 proposes to transfer a resilient part of the sealing engagement from the beverage production device to the capsule. The advantage is that any resilient sealing member is only used once (i.e. only with the associated capsule) such that a proper functioning of the sealing can be assured and no hygienic problems can occur at the sealing member. Following from EP1700548, the capsule comprises a dedicated hollow sealing member on the outer surface of the capsule for achieving a sealing effect between an enclosing member of the beverage production device and a capsule holder (of the production device).